External Display breaks on macOS Monterey 12.2

[evanb9]

After updating to Monterey 12.2.1, my external monitor no longer registers in its previous (correct) resolution. Its muuuuch lower now. I changed settings in my normal 1920x1080 resolution isnt even an option (yes I tried option+click and SMC reset). I have a second external monitor and that too has a poor resolution now. Also, some of my USB-C ports will randomly stop workign and will only resume working if I restart.
I'm a dev and need my monitors, this is actually a massive hampering to my productivity. Anyone else experiencing issues with their external displays after upgrading?

My monitor is a Samsung 31.5inch curbed curved glass monitor. My other one is just a normal 32inch Samsung. Both using HDMI-USB-C

 

[joevt]

What Mac and GPU are you using?

What model of Samsung?

Did you try SwitchResX?

I would use OCLP or gibMacOS to download previous Monterey version, install to a new partition, then get output from AllRez and AGDCDiagnose in both versions of Monterey and compare to see what changed (especially the list of modes listed by AllRez).
https://forums.macrumors.com/thread...-on-mac-pro-yes-you-can.2309750/post-30760662

 

[straydoug]

Not the exact same issue, but I've got a new 2021/M1 16" MBP running Monterey 12.2 and am unable to have more than 2 of my 4 attached external monitors display at once.

My older 2019/i9 16" MBP running Big Sur 11.6.3 has no problem displaying to these 4 monitors (they aren't high-res or anything), however because of some documented heat issues with the 2019/i9 model, I periodically experience that laptop slowing to a crawl unless I unplug the external monitors. This was the #1 reason I am upgrading to a new device, to boost my productivity with my multi-monitor setup... and as frustrating as the slowdown performance issues were with the 2019/i9 machine, at least the monitors DISPLAYED and worked without issue a reasonable percentage of the time.

So I'm reverting to use my 2019/i9 machine until this issue is resolved... I'm hoping it's OS-related and will be resolved rather than a hardware issue with the 2021/M1 which will be unresolvable. Unfortunately it's a work-managed computer, so I can't roll back the OS to see if a prior version would work better with the external monitors.

 

[mve0991]

I have the exact same issue after upgrading to Monterey 12.2.1 yesterday. Did you already found a solution?

 

[higlon]

I have also this problem after the update to 12.2.1. Unfortunately, I have not yet found a solution for this. I have tried the following tasks so far:

• delete /Library/Preferences/com.apple.windowserver.plist and ~/Library/Preferences/ByHost/com.apple.windowserver* and reboot
• SMC and NVRAM reset

I have also installed the RDM tool. I can change the resolution with this tool back to my favorite one. But the text is then blurred. So this is not a solution for me.

I am using a LG monitor with a Thunderbolt 3 cable (original cable from Apple). I want to try the next hours and connect my MacBook Pro 15" (2018) via Thunderbolt/HDMI to the monitor to check is this will fix the problem.

Edit: I have connected my LG monitor via a Thunderbolt hub via HDMI cable. Unfortunately, that did not solve the problem either.

Edit2: Updated the firmware from my LG monitor yesterday. This did also not fix the problem.

 

[seanhealy]

I'm seeing this issue on my M1 Max & external display after the latest update as well. Hopefully something they resolve soon here.

 

[straydoug]

Yikes, I didn't realize M1 Pro chip is a downgrade from previous Intel chips in terms of display support... only supports 2 external monitors (whereas older Intel models as well as M1 Max support 4 external monitors).

 

[joevt]

Yikes, I didn't realize M1 Pro chip is a downgrade from previous Intel chips in terms of display support... only supports 2 external monitors (whereas older Intel models as well as M1 Max support 4 external monitors).

Which Intel chip supports 4 external monitors? The most powerful Intel GPU on a Mac is https://support.apple.com/kb/SP819?viewlocale=en_US&locale=en_US
Intel chips only support 3 displays total.
M1 Pro supports built-in display plus two external displays which is also 3 displays total so it's at least the same as an Intel GPU.
Intel can only connect one LG UltraFine 5K but M1 Pro can connect two so that's an upgrade.

I suppose you are actually referring to Intel Macs with AMD GPUs. In that case the M1 Pro is a downgrade except that it has parity when two LG UltraFine 5K displays are connected. In any case, if you want more than that, then there's the M1 Max.

 

[straydoug]

Yes, fair point, should have said “models” instead of “chips” perhaps. Many prior Intel-based models supported 4 external displays, the new M1 Pro-based models is a downgrade in this regard as it only supports 2 external displays.

 

[joevt]

the new M1 Pro-based models is a downgrade in this regard as it only supports 2 external displays

it's not a downgrade if the two displays are LG UltraFine 5K since Mac laptops with AMD could only connect two of those at 5K60 (but you can connect four of them to AMD at 4K60 each).

 

[pshufd]

Yikes, I didn't realize M1 Pro chip is a downgrade from previous Intel chips in terms of display support... only supports 2 external monitors (whereas older Intel models as well as M1 Max support 4 external monitors).

I ordered just after the launch and didn't realize that it only supported two external displays - major disappointment. I didn't want to wait longer for a Max model. I don't think that you should have to order a Max. Instead, I redesigned my desktop around 27 inch iMacs and just use the MacBook Pro as a laptop.

 

[straydoug]

it's not a downgrade if the two displays are LG UltraFine 5K since Mac laptops with AMD could only connect two of those at 5K60 (but you can connect four of them to AMD at 4K60 each).

I understand, but don’t know how to be more clear that I’m referring to a downgrade in terms of the number of monitors supported, not the resolution thereof. I have a very efficient work setup with 4 external monitors at lower resolutions and find that more effective (and affordable!) than higher res monitors. I have previously tried replacing two with a single 4K screen and found it less efficient for my needs, so have passed off the 4K screen to my kid. I simply want 4 monitors supported, and don’t care about the max supported res. To achieve that, I have to get an M1 Max (or use my older Intel/AMD-based MBP), as M1 Pro is a downgrade of this specific piece of functionality (NUMBER of external monitors supported).

 

[pshufd]

I understand, but don’t know how to be more clear that I’m referring to a downgrade in terms of the number of monitors supported, not the resolution thereof. I have a very efficient work setup with 4 external monitors at lower resolutions and find that more effective (and affordable!) than higher res monitors. I have previously tried replacing two with a single 4K screen and found it less efficient for my needs, so have passed off the 4K screen to my kid. I simply want 4 monitors supported, and don’t care about the max supported res. To achieve that, I have to get an M1 Max (or use my older Intel/AMD-based MBP), as M1 Pro is a downgrade of this specific piece of functionality (NUMBER of external monitors supported).

I bought two used 27 inch iMacs and use those instead of the MacBook Pro. The other three 27 inch monitors are running off of Windows. So I'm all Intel on the desktop now and just use the MacBook Pro as a standalone laptop. It is really good for that purpose but obviously more hardware as in your case.

 

[Slartibart]

After updating to Monterey 12.2.1, my external monitor no longer registers in its previous (correct) resolution. Its muuuuch lower now. I changed settings in my normal 1920x1080 resolution isnt even an option (yes I tried option+click and SMC reset). I have a second external monitor and that too has a poor resolution now. Also, some of my USB-C ports will randomly stop workign and will only resume working if I restart.
I'm a dev and need my monitors, this is actually a massive hampering to my productivity. Anyone else experiencing issues with their external displays after upgrading?

My monitor is a Samsung 31.5inch curbed curved glass monitor. My other one is just a normal 32inch Samsung. Both using HDMI-USB-C

you can try BetterDummy.

 

[joevt]

I understand, but don’t know how to be more clear that I’m referring to a downgrade in terms of the number of monitors supported, not the resolution thereof. I have a very efficient work setup with 4 external monitors at lower resolutions and find that more effective (and affordable!) than higher res monitors. I have previously tried replacing two with a single 4K screen and found it less efficient for my needs, so have passed off the 4K screen to my kid. I simply want 4 monitors supported, and don’t care about the max supported res. To achieve that, I have to get an M1 Max (or use my older Intel/AMD-based MBP), as M1 Pro is a downgrade of this specific piece of functionality (NUMBER of external monitors supported).

I am not denying that the M1 Pro is a downgrade in regards to the number of displays that can be connected. I am just saying there is a specific set of displays where the number of displays of that set that can be connected to the M1 Pro is not a downgrade. I understand that the set of displays I refer to does not include displays that you want to use because you want to be able to use more than two of them or because two displays with at least equal area and pixels as four displays will cost more or you don't want to buy new displays when you already have four functioning displays.

 

[pshufd]

I am not denying that the M1 Pro is a downgrade in regards to the number of displays that can be connected. I am just saying there is a specific set of displays where the number of displays of that set that can be connected to the M1 Pro is not a downgrade. I understand that the set of displays I refer to does not include displays that you want to use because you want to be able to use more than two of them or because two displays with at least equal area and pixels as four displays will cost more or you don't want to buy new displays when you already have four functioning displays.

He has a particular use case that he deems efficient for his setup. Same with me.

 

[Superken7]

I have updated my M1 MacBook Air to 12.2.1 only to find that my external monitor (connected over USB-C) no longer works. It's not just the resolution, it doesn't work at all. The monitor says "no signal". I've tried resetting macbook and monitor, and a different cable to no avail.
Are these things not even tested by Apple to meet a minimum quality anymore?

 

[SBA]

I think I'm in the same boat as others here. I am on a 2018 Mac mini (intel i7 w/ UHD 630 graphics) with 3 Dell U2520DR displays hooked up (each 2560x1440; 2 plugged into USB-C and 1 plugged into HDMI). All have been working fine from November 2020 until around the time I updated to macOS 12.2.1.

At first, the 2 hooked up via USB-C stopped working completely (they show power, but absolutely no signal on either monitor). After taking each of them down, then plugging into a different wall outlet to confirm they aren't completely broken, and then plugging back into my Mac, they started working again. Until yesterday when 1 of them stopped working with the same issue.

The same fix process worked though, but I really don't want to keep doing this. Hoping this is just a macOS bug and will be fixed soon!

 

[pswenson]

I am having the same issue.

 

[higlon]

I have yesterday installed the update to 12.3. This update did not fix the problem for me. I still use RDM to modify the display resolution.

 

[nlarzon]

I have the same issue on my MacBook Pro (13-inch, 2018, Four Thunderbolt 3 Ports) with Montaray 12.3

Is there a support ticket towards Apple? Are they aware of the problem?

 

[bohemianjapsody]

Almost the same issue here, since updating to Monterey both MBP 16" i9 and MBP 16" M1 Max don't recognise my 4K DCI monitor anymore as the 17:9 it is - but instead display it as 16:9 UHD. Thus rendering all ellipses and toad-faces. Not pretty and very annoying, and can't seem to fix it. Also my 100W Thunderbolt 3 hub and charger will only give max 60W of power all of a sudden, so I need to sacrifice another thunderbolt plug just for power on the i9 (or use the magsafe charger which normally lives in my bag for extra charging).

Quite annoyed for getting two machines two years apart for about €6000 and having to deal with this stuff.

Anyone found any solution yet? I'll check Genius Bar in a few days.

 

[adrianstuartt]

I have the same issue on my MacBook Pro (13-inch, 2018, Four Thunderbolt 3 Ports) with Montaray 12.3

Is there a support ticket towards Apple? Are they aware of the problem?

Can no longer detect 2nd display i… | Apple Developer Forums

developer.apple.com

Decided to try and connect my early 2020 mba via hdmi output from a usb-c dock (with PD, 100w charger connected) to my LG 27" 144hz monitor, for the first time ever, and had this thrown in my face. LOL

 

[Snowman94]

I have updated my M1 MacBook Air to 12.2.1 only to find that my external monitor (connected over USB-C) no longer works. It's not just the resolution, it doesn't work at all. The monitor says "no signal". I've tried resetting macbook and monitor, and a different cable to no avail.
Are these things not even tested by Apple to meet a minimum quality anymore?

I'm having the same issue with a new Thunderbolt Display I bought–works on my intel air, but not on my M1 air. M1 is connected using an official apple dongle. :-(